Sight glass assembly

ABSTRACT

A sight glass assembly generally including a housing structure having an opening therethrough, the opening having an enlarged section providing a shoulder, a face plate having an opening registered with the opening in the housing structure, detachably mounted on the housing structure in opposed relation to the shoulder, a lens disposed tin the enlarged section of the opening in the housing structure and interposed between the shoulder and the face plate, sealing means disposed in the enlarged section of the opening in the housing structure, between the lens and the housing structure, and means engageable with the sealing means for compressing the sealing means against the face plate to expand the sealing means laterally thereby providing a positive seal between the lens and the housing structure.

Meginnis 1 SIGHT GLASS ASSEMBLY [76] lnventor: Charles E. Meginnis, 529% Nancy St., Charleston, W. Va.

[22] Filed: Apr. 29, 1971 [21] Appl. No.: 138,546

[521 U.S. Cl. 350/319, 73/334 [51] Int. Cl. G021) 7/00 {58] Field of Search 350/319; 73/330, 73/334; 220/82 A;'l37/559; 116/117 C [56] References Cited UNITED STATES PATENTS 3,345,872 10/1967 Menginnis 73/330 UX 3,340,890 9/1967 Raskhodoff.. 3,438,540 4/1969 Le Roy 3,625,390 12/1971 Menginnis.... 2,942,469 6/1960 Le Roy 73/334 FOREIGN PATENTS OR APPLICATIONS 141,781 7/1919 Great Britain 73/334 '[451 July 17, 1973 Primary Examiner lohn K. Corbin Att0rneyMason, Fenwick & Lawrence 571 ABSTRACT A sight glass assembly generally including a housing structure having an opening thercthro ugh, the opening having an enlarged section providing a shoulder, a face plate having an opening registered with the opening in the housing structure, detachably mounted on the housing structure in opposed relation to the shoulder, a lens disposed tin the enlarged section of the opening in the housing structure and interposed between the shoulder and the face plate, sealing means disposed in the enlarged section of the opening in the housing structure, between the lens and the housing structure, and means engageable with the sealing means for compressing the sealing means against the face plate to expand the sealing means laterally thereby providing a positive seal between the lens and the'housing structure.

l4 Claims, 6 Drawing Figures PAIENTEDJUU7'975 3.746.431

SHEU l UF 2 v 23 L za C I INVENIUR. CHAQLE: E. Msamms SIGHT GLASS ASSEMBLY This invention relates to a sight glass assembly, and more particularly to a sight glass assembly suitable for large capacity vessels containing corrosive fluids.

' In the prior art, sight glass assemblies adapted for use with gas'or liquid containers often are provided with a resilient packing member which is compressed and thus expanded to form a fluid tight seal between the lens and the housing structure for the lens which is secured to the fluid container. Usually, the packing member is exposed to the interior of the container, so that it is subject to corrosion caused by contact with the fluid within the container. In addition, the housing structure may be exposed to the interior of the container, so that it also is subjected to corrosion caused by contact with the fluid in the container.

In my invention as described and claimed in US. provided a sight glass assembly particularly adapted for use with containers containing corrosive fluids. Such invention includes an insert consisting of a corrosive resistant material which is interposed between the sealing means and the housing structure of the assembly, and which includes an inwardly extending annular flange portion interposed between the sealing means and the housing structure, on the one hand, and the opening in the housing structure, on the other hand, for shielding the packing member from the deteriorative action caused by contact with the housing structure, and the corrosive action caused by contact with the fluid within the 9container. Such insert further functions to shield the housing structure of the sight glass assembly from the corrosive effects of the fluid within the container on which the sight glass assembl is mounted.

Although the use of an insert as prvided in my aforementioned invention has been found to be highly effective in prolonging the lives of the components of a sight glass assembl/ and assuring maintenance free operation of the sight glass over an extended period of service, it further has been found that the use of such an insert increases the cos t of such assemblies. It thus has been found desirable to provide a sight glass assembly of the type disclosed in the aforementioned patent, wherein a more inexpensive means is provided for protecting the components of the assembly while providing a means for supporting the lens within the housing structure of the assembly, and forming a positive fluid tight seal between the periphery of the lens and the housing structure.

Accordingly, it is the principal object of the present invention to provide an improved sight glass assembly.

Another object of this invention is to provide an improved sight glass assembl for a gluid container, wherein the sealing means disposed between the sight glass and the housing structure for the sight glass is shielded from the corrosive action of the fluid within the container.

A further object of this invention is to provide an improved sight glass assembly having the lens thereof mounted within a metallic housing structure, wherein the sealing means interposed between the periphery of the lens and the housing structure is shielded from any corrosive action otherwise caused by contact with the fluid within the container.

A still further object of this invention is to provide an improved sight glass assembly for fluid containers containing corrosive gases or liquids, wherein noncorrosive resistant sealing means may be used to form a seal between the lens and the housing structure for the sight glass. I

Another object of the present invention is to provide an improved sight glass assembly for a fluid container, wherein there is provided a fluid tight seal between the sight glass and the housing structure for the sight glass for the useful life of the assembly.

A further object of the present invention is to provide an improved sight glass assembly for containers containing corrosive gases or liquids, which is simple in construction, easy to assemble and inexpensive to man-' ufacture.

Other objectsand advantages of the present invention will become more apparent to those persons skilled in the art, from the following description taken in conjunction with the accompanying drwaings, wherein:

FIG. 1 is a top plan view of an embodiment of the invention;

FIG. 2 is an enlarged cross-sectional vew taken along line 2-2 in FIG. 1;

FIG. 3 is an exploded view of the embodiment illustrated in FIGS. 1 and 2;

FIG. 4 is a top plan view of another embodiment of the invention;

FIG. 5 is an enlarged cross-sectional view taken along line 55 in FIG. 4; and

FIG. 6 is an exploded view of the embodiment illustrated in FIGS. 4 and 5.

Briefly described, the present invention provides an improved sight glass assembly generally including a housing structure having an opening therethrough, the opening having an enlarged section providing a shoulder, a face plate having an opening registered with the opening in the housing structure, detachably mounted on the housing structure in opposed relation to the shoulder, a lens disposed in the enlarged section of the opening in the housing structure and interposed between the shoulder and the face plate, sealing means disposed in the enlarged section of the opening in the housing structure, between the lens and the housing structure, and means engageable with the sealing means for compressin the sealing means against the face plate to expand the sealing means laterally, thereby providing a positive seal between the lens and the housing structure.

7 Preferably, the face plate consists of, or is coated with a corrosive resistant material, the enlarged section of the opening in the housing structure is provided with a liner or a coating of a corrosive resistant material intcrposed between the sealing means and the housing structure, the compressing means includes a rigid member disposed in the enlarged section of the housing.

structure, engageable with the sealing means, and the housing structure includes a plurality of threaded openings provided with set screws engageable with the rigid member for compressing the sealing means against the face plate, causing it to expand laterally to form a fluid tight seal between the periphery of the lens and the housing structure.

Referring to FIGS. 1 through 3, there is illustrated a first embodiment of the invention. Specifically, there is illustrated a fluid containe 10 having a circular opening 11 therein and a sight glass assembly 12 secured to the fluid container. The sight glass assembly includes a housing structure 13 which may consist of gray cast iron, having an opening 14 adapted to register with the opening 11 in the fluid container. The housing structure is secured to the fluid container by means of a plurality of bolts 15 extending through suitable openings 16 circumferentially spaced in the housing structure, which are adapted to register with suitable threaded holes in the fluid container. The opening 14 in the housing structure is provided with an enlarged section 17 which providesan annular upper shoulder 18. Mounted on the shoulder 18 is a gasket 19 and a circular lens 20 having a diameter less than the diameter of the enlarged section 17. Disposed on the cylindrical wall of the enlarged section 17 is a coating 21 of a corrosive resistance material, such as glass. The coating 21 extends beyond the enlarged section 17 onto the surface 21 of the housing structure, as indicated at 21a. Detachably secured to the housing structure 13 by means of a plurality of bolts 23 is an annular face plate 24 having an inner diameter less than the outside diameter of the lens 20 and an outside diameter greater than the diameter of the enlarged section 17 of the opening 14, so that when the annular face plate is mounted on the housing structure 13, as illustrated in FIG. 2, the face plate will support the lens 20, and the main body thereof will bridge the annular space between the lens 20 and the housing structure 13. The face plate 24 consits of a metallic material having a coating 25 of a corrosive resistant material, such as glass. As best illustrated in FIG. 2, an annular gasket 26 is interposed between the housing structure and the periphery of the lens 20, and the face plate 24, so that the lens 20 will be interposed between the annular shoulder 18 and the annular face plate 24,'and provided with annular gaskets 19 and 26 to prevent contact of the lens 20 with a rigid contact surface. As shown in FIG. 2, the opening 11 in the fluidcontainer 10 is provided with an enlarged annular section 27 for receiving the annular face plate 24 when the sight glass assembly is mounted on the fluid container 10. To prevent contact of the face plate 24 with the wall of the fluid container, an annular gasket 28 is provided on the annular shoulder of the enlarged section 27.

v A fluid tight seal is provided between the periphery of the lens 20 and the housing structure 13, by means of a retainer ring 29, an annular resilient packing'member and a compression ring 31. The retainer ring 29 preferably consists of a corrosive resistant material such as Teflon and is disposed in the enlarged section 17 of the opening 14, seated on the gasket 26. The packing member 30 may consist of Teflon or Teflon impregnated with asbestos and is interposed between the periphery of the lens 20 and the coating 21 within the enlarged section 17. The compression ring 31 is seated on the packing member 30 and is partially received within an annular recess 32 provided in the annular shoulder 18 of the housing structure. The housing lens 20 to form a fluid tight seal between the periphery of the lens 20 and the coating 21 of the housing structure to prevent leakage of fluid within the container 10 through the sight glass assembly, and to place the lens 20 in radial compression, thereby preventing blowout of the lens 20 in the event of breakage of the lens.

It is contemplated that the sight glass assembly including the housing structure 13, the face plate 24, the lens 20, retainer ring 29, packing member 21, compression ring 31 and the various gaskets therefor, will be assembled as an integral unit, so that the assembly can be installed on a fluid container 10 merely by positioning the housing structure '13 on the wall of the fluid container with the face plate 14 received within the enlarged section 27 of the wall of the container, and securing the entire assembly to the wall of the container by means of the bolts 15. In the event of failure of any of the components of the assembly, the assembly may easily be removed from the wall of the container, disassembled to replace any defective component and then easily installed again on the wall of the container.

FIGS. 4 through 6 illustrate a second embodiment of the invention which is similar to the above mentioned compression ring 39, a circular lens 40, a packing ring I 41, a retainer ring 42, a gasket 43 and an annular face plate 44. As best illustrated in FIG. 5, the housing structure 37 is provided with an opening 45 which is adapted to register with the opening 34 in the wall of the container 10a when the sight glass assembly is mounted on the wall of the container. The opening 45 is provided with an enlarged section 46 providing an annular shoulder 47. The annular liner 38 consists of a substantially rigid, corrosive resistant material such as stainless steel or titanium, and is press fit within the enlarged section 46 of the opening 45 with the annular flange portion 38a engaging the surface 48 of the hous-v ing structure.

The lens 40 has a diameter larger than the diameter of the opening 45 and the inside diameter of the face plate 44, and smaller than the diameter of the enlarged section 46 of the opening 45, so that when the lens is inserted in the housing structure and the annular face. plate 44 is secured to the housing structure with bolts 49, as illustrated in FIG. 5, the lens will be interposed between the annular shoulder 47 and the annular face plate 44, providing an annular space between the periphery of the lens and the annular liner 38. Glass to metal contact of the lens 40 is prevented by means of an annular gasket 50 interposed between the lens 40 and the annular shoulder 47 of the housing structure, and the annular gasket 43 interposed between the lens 40 and the housing structure 37, and the annular face plate 44. Similar to the face plate 24 as shown in FIG. 2, the annular face plate 44 has an inside diameter less than the diameter of the lens 40 and an outside diameter greater than the diameter of the enlarged section 46 of the opening 45, so that the annular face plate hears upon the lens 40 and the housing structure, and bridges the annular space provided between the liner 38 and the periphery of the lens 40.

The face plate 44 consists of a corrosive resistant material, such as stainless steel or titanium, and is received within an enlarged section 51 of the opening 34 in the wall of the fluid container when the sight glass assembly is mounted on the fluid container. As shown in FIG. 5, an annular gasket 52 is interposed between the face plate 44 and the shoulder of the enlarged section 51.

The retainer ring 42 and the packing ring 41 are disposed within the enlarged section 46 between the periphery of the sight glass and the liner 38. The packing ring 41 is compressed by the compression ring 39 to cause the packing ring 41 to expand laterally or radially relative to the axis of the lens 40, to form a fluid tight seal between the periphery of the lens and the liner 38, and to place the lens in radial compression. As shown in FIG. 5, the compression ring 39 partially projects into an annular recess 53 in the annular shoulder 47 of the housing structure, and is forced downwardly by a plurality of set screws 54 threaded into a plurality of circumferentially spaced threaded openings 55 in the housing structure, communicating with the annular recess 53.

In each of the above described embodiments, it will be noted that the liner or coating of corrosive resistant material provided between the packing member and the housing structure prevents the packing member from deteriorating by preventing contact with the hous ing structure. This would permit the selection of a packing or sealing material without concern for the possible deleterious effects of the packing material with the particular material of the housing structure. In addition, it is to be noted that the interposition of the annular face plate member in each of the embodiments shields both the packing member and the housing structure from the possible corrosive effects of the fluid contained within the fluid container. This again would permit the selection of a material for the packing member without concern for the possible effects of the fluid within the container coming into contact with th packing member. In addition, this further would permit the selection of a material for the housing structure without being concerned for the possible corrosive effects of the fluid within the container on the material of the housing structure. in both instances, it is contemplated that a wider selection of materials would be available for the packing member and the housing structure, which ultimately has the effect of reducing the cost of the entire sight glass assembly.

From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention which come within the province of those skilled in the art. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof as limited solely by the appended claims.

What I claim is:

1. A sight glass assembly comprising a housing strucdisposed in the enlarged section of the opening in said housing structure, and means engageable with said' sealing means for compressing said sealing means against said substantially planar surface of said face plate to expand said sealing means laterally thereby providing a positive seal between said lens and said housing structure.

2. A sight'glass assemblyaccording to claim 1, wherein said face plate consists of a corrosive resistance material.

3. A sight glass assembl according to claim 1, wherein said face plate is coated with a corrosive resistance material.

4. A sight glass assembly according to claim 1, including a corrosive resistant liner permanently disposed on the wall of said enlarged section of said opening, interposed between said sealing means and said housing structure.

5. A sight glass assembly according to claim 1, v

wherein said compression'means includes a rigid member disposed in the enlarged section of the housing structure, and enageable witl said sealing means, and wherein said housing structure includes threaded openings provided with set screws engageable with said rigid member.

6. A sight glass assembly according to claim 1, wherein the wall of the enlarged section of said opening in said housing structure is provided with a coating of a corrosive resistant material.

7. A sight glass assembly according to claim 1, wherein the portion of said housing structure engaged by said sealing means and said face plate are coated with a corrosive resistant material.

8. A sight glass assembly according to claim 7, wherein said corrosive resistant material is glass.

9. A sight glass assembly according to claim 1, wherein the opening in said housing structure, the enlarged section of the opening in said housing structure and said lens are circular, and wherein said face plate and said sealing means are annular, whereby upon compressing said sealing means against said face plate, said sealing means is expanded radially relative to the axis of said lens to provide a positive seal between said lens and said housing structure, and said lens is placed in radial compression.

10. A sight glass assembly according to claim 9, wherein said face plate consists of a corrosive resistant material.

11. A sight glass assembl/ according to claim 9, wherein said face plate is coated with a corrosive resistant material.

12. A sight glass assembly according to claim 9, including a corrosive resistant annular liner permanently disposed on the wall of said enlarged section of said opening interposed between said sealing means and said housing structure. 7 g

13. A sight glass assembly according to claim 9,wherein the wall of the enlarged section of said opening in said housing structure is provided with a coating of a corrosive resistant material.

14. A sight glass assembly according to claim 9, wherein the portion of said housing structure engaged by said sealing means and said face plate are coated with a corrosive resistant material.

seem: 

1. A sight glass assembly comprising a housing structure having an opening therethrugh, said opening having an enlarged section providing a shoulder, a face plate having an opening registered with the opening in said ousing structure, detachably mounted on said housing structure in opposed relation to said shoulder, a lens disposed in the enlarged section of the opening in said housing structure and interposed between said shoulder and said face plate, said face plate having a sub-stantially planar surface supporting said lens and engageable with said housing structure, sealing means disposed in the enlarged section of the opening in said housing structure, and means engageable with said sealing means for compressing said sealing means against said substantially planar surface of said face plate to expand said sealing means laterally thereby providing a positive seal between said lens and said housing structure.
 2. A sight glass assembly according to claim 1, wherein said face plate consists of a corrosive resistance material.
 3. A sight glass assembl according to claim 1, wherein said face plate is coated with a corrosive resistance material.
 4. A sight glass assembly according to claim 1, including a corrosive resistant liner permanently disposed on the wall of said enlarged section of said opening, interposed between said sealing means and said housing structure.
 5. A sight glass assembly according to claim 1, wherein said compression means includes a rigid member disposed in the enlarged section of the housing structure, and enageable witl said sealing means, and wherein said housing structure includes threaded openings provided with set screws engageable with said rigid member.
 6. A sight glass assembly according to claim 1, wherein the wall of the enlarged section of said opening in said housing structure is provided with a coating of a corrosive resistant material.
 7. A sight Glass assembly according to claim 1, wherein the portion of said housing structure engaged by said sealing means and said face plate are coated with a corrosive resistant material.
 8. A sight glass assembly according to claim 7, wherein said corrosive resistant material is glass.
 9. A sight glass assembly according to claim 1, wherein the opening in said housing structure, the enlarged section of the opening in said housing structure and said lens are circular, and wherein said face plate and said sealing means are annular, whereby upon compressing said sealing means against said face plate, said sealing means is expanded radially relative to the axis of said lens to provide a positive seal between said lens and said housing structure, and said lens is placed in radial compression.
 10. A sight glass assembly according to claim 9, wherein said face plate consists of a corrosive resistant material.
 11. A sight glass assembl/ according to claim 9, wherein said face plate is coated with a corrosive resistant material.
 12. A sight glass assembly according to claim 9, including a corrosive resistant annular liner permanently disposed on the wall of said enlarged section of said opening interposed between said sealing means and said housing structure.
 13. A sight glass assembly according to claim 9,wherein the wall of the enlarged section of said opening in said housing structure is provided with a coating of a corrosive resistant material.
 14. A sight glass assembly according to claim 9, wherein the portion of said housing structure engaged by said sealing means and said face plate are coated with a corrosive resistant material. 